1. Field of the Invention
The invention relates to a connector terminal of a female electric connector, including a contact portion and a spring portion between which a male connector terminal of the male electric connector is sandwiched to thereby make electrical contact with the male connector terminal.
2. Description of the Related Art
A connector terminal for sandwiching therebetween a male connector terminal of a male electric connector is used to thereby electrically connect printed circuit boards to each other or a cable to a printed circuit board.
For instance, Japanese Utility Model No. 2579908 has suggested a connector including a spring terminal.
FIG. 21 is a plan view of the spring terminal 50 suggested in the above-identified Japanese Utility Model, and FIG. 22 is a cross-sectional view of a housing into which the spring terminal 50 is inserted.
As illustrated in FIGS. 21 and 22, the spring terminal 50 includes a leg 51, a straight portion 53 passing through a terminal holder 52 of an electrically insulating housing 70 and extending along a support 71 of the housing 70, a first bending portion 54 bending almost perpendicularly from the straight portion 53, a second bending portion 55 downwardly bending along the support 71, a first necking portion 56 for holding a male connector 60, an almost semi-circular bottom 57 extending along a bottom 72 of the housing 70, a second necking portion 58 located symmetrically with the first necking portion 56, and a free end 59 extending symmetrically with the second bending portion 55, and making engagement with a projection B of the housing 70.
FIG. 23 is a perspective view of a connector suggested in Japanese Patent Application Publication No. H10 (1998)-284193.
The connector 80 electrically connecting a terminal pin 85 to a printed circuit board 90 includes a pair of pin contacts 81 each making electrical contact with the terminal pin 85, a pair of arms 82 each extending outwardly from the pin contact 81 and deformable when pressurized, and a pair of contacts 83 each formed at a distal end of the arm 82 and making electrical contact with the printed circuit board 90.
The printed circuit board 90 is formed with an opening 91 into which the pin contacts 81 are inserted, and openings 92 into which the contacts 83 are inserted.
However, the above-mentioned spring terminal and connector are accompanied with problems as follows.
In the spring terminal 50 illustrated in FIGS. 21 and 22, when the male connector 60 is inserted into the spring terminal 50, the second necking portion 58 is outwardly deformed. Hence, the free end 59 located adjacent to the second necking portion 58 is caused to outwardly move, resulting in that a contact pressure which the second necking portion 58 exerts on the male connector 60 is reduced. Thus, reliability in electrical connection between the spring terminal 50 and the male connector 60 is unavoidably deteriorated.
As an alternative, if the male connector 60 is inserted into the spring terminal 50 with the male connector 60 being slipped towards the second necking portion 58, the second necking portion 58 is caused to further outwardly be deformed, in which case, since the male connector 3 more intensively compresses the second necking portion 58, a contact pressure which the second necking portion 58 exerts on the male connector 60 is increased. However, since the male connector 60 moves away from the first necking portion 56, a contact pressure which the first necking portion 56 exerts on the male connector 60 is unavoidably reduced.
In the connector 80 illustrated in FIG. 23, even if the terminal pin 85 were inserted between the pin contacts 81, since the pin contacts 81 are inserted into the opening 91, a space between the pin contacts 81 would not be spread. Accordingly, it is possible to avoid reduction in a contact pressure which the pin contacts 81 exerts on the terminal pin 85.
However, if a positional relation between an electric unit including the terminal pin 85 and the printed circuit board 90 were deflected, a contact pressure which the pin contact 81 located remote from the terminal pin 85 exerts on the terminal pin 85 would be unavoidably reduced, resulting in deterioration in reliability in electrical connection between the terminal pin 85 and the connector 80.
As mentioned above, if a male connector is inserted into a female connector with a positional relation between them being deflected, a contact pressure which the female connector exerts on the male connector is reduced, and further, the male and female connectors has a risk of being buckled.
Furthermore, a positional relation between male and female connectors is generated even after a male connector is inserted into a female connector. In particular, in an electric connector equipped in an automobile, a positional relation between a printed circuit board on which a female connector is mounted and another printed circuit board on which a male connector is mounted is prone to be deflected due to oscillation generated while an automobile is running, and a difference in thermal expansion caused by temperature fluctuation around the printed circuit boards. Though the deflection in the positional relation can be suppressed when one of housings is fit into the other, deflection in clearances of the housings is generated. Thus, each time a male connector moves when an automobile oscillates, it is important for a female connector to provide reliability in electrical connection with the male connector.